When Incest Is Best: Kissing Cousins Have More Kin!

Study analyzing more than 200 years of data finds that couples consisting of third cousins have the highest reproductive success

It is not quite incest. And though it will increase your chances of birthing a healthy baby, it is a bit unorthodox, to say the least. Still, scientists at Icelandic biotechnology company deCODE genetics say that when third and fourth cousins procreate, they generally have scads of kids and grandkids (relative to everyone else).

It has long been wondered exactly how kinship influences reproductive success. Previous studies have uncovered positive correlations, but the biological data has been clouded by socioeconomic factors (such as average marrying age and family size) in those populations in which consanguineous marriage is commonplace, such as in India, Pakistan and the Middle East. The new study, however, was able to shed light on the biological reason for the earlier findings.

Scientists came to their conclusions after studying the records of more than 160,000 Icelandic couples with members born between 1800 and 1965. “The advantage of using the Icelandic data set lies in this population being small and one of the most socioeconomically and culturally homogenous societies in the world,” the researchers report in Science, “with little variation in family size [and] use of contraceptives and marriage practices, in contrast with most previously studied populations.”

The results of the exhaustive study are constant throughout the generations analyzed. Women born between 1800 and 1824 who mated with a third cousin had significantly more children and grandchildren (4.04 and 9.17, respectively) than women who hooked up with someone no closer than an eighth cousin (3.34 and 7.31). Those proportions held up among women born more than a century later when couples were, on average, having fewer children.

Despite the general pattern for reproductive success favoring close kinship, couples that were second cousins or more closely related did not have as many children. The most likely reason, scientists say: offspring of such close relatives were likely to have much shorter life spans, because of the chance of inheriting harmful genetic mutations.

“With close inbreeding—between first cousins—there is a significant increase in the probability that both partners will share one or more detrimental recessive genes, leading to a 25 percent chance that these genes will be expressed in each pregnancy,” says Alan Bittles, director of the Center for Human Genetics at Edith Cowan University in Joondalup, Australia, who was not involved in the study.

Interestingly, one evolutionary argument for mating with a relative is that it might reduce a woman’s chance of having a miscarriage caused by immunological incompatibility between a mother and her child. Some individuals have an antigen (a protein that can launch an immune response) on the surface of their red blood cells called a rhesus factor—commonly abbreviated “Rh.” In some cases—typically during a second pregnancy—when a woman gets pregnant, she and her fetus may have incompatible blood cells, which could trigger the mother’s immune system to treat the fetus as a foreign intruder, causing a miscarriage. This occurrence is less probable if the parents are closely related, because their blood makeup is more likely to match.

“It may well be that the enhanced reproductive success observed in the Iceland study at the level of third [and] fourth cousins, who on average would be expected to have inherited 0.8 percent to 0.2 percent of their genes from a common ancestor,” Bittles says, “represents this point of balance between the competing advantages and disadvantages of inbreeding and outbreeding.”

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He said he punched a woman for calling him Nigger. A jury called it murder.

Robert Coleman, 27, was found guilty of second-degree murder Monday in Alexandria Circuit Court. (Alexandria Detention Center)

 

“We of course remain disappointed that they didn’t see it as manslaughter,” Coleman’s attorney, Robert Jenkins, said after the jury returned. He said Coleman and his family were “grateful” for the jury’s recommended sentence, given that second-degree murder can carry a punishment of up to 40 years. It reflected, Jenkins said, “that this was not something that he wanted to happen, that he did not intend to take someone’s life.”

A judge will formally sentence Coleman on May 24, but deviations from jury recommendations are rare. He is being held at the Alexandria Detention Center.

“In an all-too-often repeated theme, a tragedy unfolded because of a defendant’s inability to tolerate a perceived slight,” Commonwealth’s Attorney Bryan Porter said in a statement. “Verbal arguments should never devolve into physical altercations because physical altercations often bring devastating consequences.”

[Woman assaulted outside a convenience store in Alexandria dies]

Coleman and Montiel-Benitez were strangers. Coleman was buying cigarettes. Montiel-Benitez was buying alcohol at the convenience store near the Mark Center on Seminary Road.

The source of the animosity between them remains a mystery. Surveillance video shows they engaged in a brief conversation, but there is no audio. Coleman’s girlfriend, Nikki Howard, testified she could not hear the entire conversation but broke the two up. In the video, Montiel-Benitez is seen walking to Coleman says that is when she called him the n-word; Howard remembered her cursing. In the video Coleman can be seen chasing Montiel-Benitez outside.

 

Through the leaves of a tree, another camera captures the punch that put Montiel-Benitez in a coma from which she did not recover.

Coleman fled the scene and was picked up the next day when a detective recognized him in the surveillance video. He at first denied involvement in what he thought was simply an assault. When he was told Montiel-Benitez was in critical condition, he admitted hitting her, but said he had not meant to cause serious harm.

He also thought the heavyset woman with short hair was a man, he told detectives.

Lord argued the focus on Montiel-Benitez’s appearance at trial, as well as the high level of alcohol in her system, was disrespectful to the dead.the door and then turning.

“She deserves to be treated with more humanity,” he told the jury.

He said Coleman was “a bully who was looking for a fight” and picked on Montiel-Benitez, who was just trying to get away.

Jenkins told jurors Montiel-Benitez’s .351 blood alcohol level and size might help explain why Coleman believed “this was going to be mutual combat, and he struck first.”

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